﻿///////////////////////////////////////////////////////////////////////////////
//
//  This source is part of the  "Managed Task Framework.NET Runtime"  (MTF.NET Runtime).
//
//
//  Copyright (c) 2011, Multicore Consulting Limited (UK)
//  All rights reserved.
//  http://www.multicoreconsulting.co.uk
//
//  Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions
//  are met:
//
//  -  Redistributions of source code must retain the above copyright
//     notice, this list of conditions and the following disclaimer.
//  -  Redistributions in binary form must reproduce the above copyright
//     notice, this list of conditions and the following disclaimer in
//     the documentation and/or other materials provided with the
//     distribution.
//  -  Neither the name of Multicore Consulting Limited nor the names of
//     its contributors may be used to endorse or promote products
//     derived from this software without specific prior written
//     permission.
//
//  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
//  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
//  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
//  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
//  COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
//  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
//  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
//  LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
//  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
//  LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
//  ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
//  POSSIBILITY OF SUCH DAMAGE.
//
///////////////////////////////////////////////////////////////////////////////

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace MTFOrg.MTF.MTFRuntime
{
    /// <summary>
    /// Singleton class for managing interface instances.
    /// </summary>
    internal class InterfaceManager
    {
        /// <summary>
        /// Singleton instance.
        /// </summary>
        private static InterfaceManager m_Instance = null;

        /// <summary>
        /// Dictionary of interfaces.
        /// </summary>
        private Dictionary<string, object> m_Interfaces;

        /// <summary>
        /// Constructor.
        /// </summary>
        /// <exception cref="System.OutOfMemoryException" />
        private InterfaceManager()
        {
            try
            {
                m_Interfaces = new Dictionary<string, object>();
            }
            catch (OutOfMemoryException)
            {
                throw;
            }
            catch (Exception e)
            {
                ErrorLog.Write(e);
            }
        }

        /// <summary>
        /// Gets the singleton interface manager instance.
        /// </summary>
        /// <exception cref="System.OutOfMemoryException" />
        private static InterfaceManager Instance
        {
            get
            {
                if (m_Instance == null)
                    m_Instance = new InterfaceManager();

                return m_Instance;
            }
        }

        /// <summary>
        /// Registers an interface with its unique ID.
        /// </summary>
        /// <param name="uniqueId">Unique identifier used to retrieve the interface</param>
        /// <param name="ifceObject">Interface object to register</param>
        /// <exception cref="System.ArgumentNullException" />
        /// <exception cref="System.OutOfMemoryException" />
        /// <exception cref="MTFOrg.MTF.MTFRuntime.InterfaceAlreadyRegisteredException" />
        public static void Register(string uniqueId, object ifceObject)
        {
            if (uniqueId == null)
                throw new ArgumentNullException("uniqueId", "InterfaceManager.Register(): Unique id must not be null.");

            if (ifceObject == null)
                throw new ArgumentNullException("ifceObject", "InterfaceManager.Register(): Interface object must not be null.");

            if (Instance.m_Interfaces.ContainsKey(uniqueId))
                throw new InterfaceAlreadyRegisteredException("InterfaceManager.Register(): Interfaces must not be registered with an ID that is already in use.");

            try
            {
                // Add the interface object into the interfaces dictionary
                Instance.m_Interfaces.Add(uniqueId, ifceObject);
            }
            catch (ArgumentException e)
            {
                ErrorLog.Write(e);
            }
        }

        /// <summary>
        /// Finds the interface with the specified unique ID.
        /// </summary>
        /// <param name="uniqueId">Unique identifier of interface to retrieve</param>
        /// <returns>Interface object registered with the specified ID, or null if not found</returns>
        /// <exception cref="System.ArgumentNullException" />
        /// <exception cref="System.OutOfMemoryException" />
        public static object Find(string uniqueId)
        {
            if (uniqueId == null)
                throw new ArgumentNullException("uniqueId", "InterfaceManager.Find(): Unique id must not be null.");

            object ifceObject = null;

            try
            {
                if (Instance.m_Interfaces.ContainsKey(uniqueId))
                    ifceObject = Instance.m_Interfaces[uniqueId];
            }
            catch (ArgumentNullException e)
            {
                ErrorLog.Write(e);
            }
            catch (KeyNotFoundException e)
            {
                ErrorLog.Write(e);
            }

            return ifceObject;
        }
    }
}